Drier.



c; F. sTEHLuN.

DRIER.

APPLICATION FILED MAR. 18, 19,15.-

U17/MMU AHORA/n.5,

CULUMBIA MANOGRAPH C0.,wASmNuToN,.D. C.

C. F. STEHLIN.

DRIER.

APPLICATION FILED MAII. Ia. |915.

1,167,853. Patented 'Jim1-11, 1916.

2 SHEETS-SHEET 2.

W/T/VESSES I W'' y 29 Anon/VHS f narran erarss DRIER,

Speccationof Letters Patent.

Patented aan. ii, 1ere.

Y Application filed March 18, 1915. Serial No. 15,165.

To all 'whom t may concern Be it known that I, CHARLES F. STEHLIN, a citizen of the United States, and a resident of New Rochelle, county of estchester, and State of New York, have invented certain new and useful Improvements in Driers, of which the following is a specification.

My invention relates to driers, and more particularly to driers of the class comprising an inclined rotating drum through which the material'to be dried is fed in a downward direction, and a drying fluid, as air, is passed in the opposite direction.

lVhile driers may be and preferably are initially constructed to embody my invention, it is readily possible to change over driers already in place to embody the invention by making certain comparatively small changes therein, having to do more especially with the arrangement of air conducting conduits and'air controllingand distributing partitions arranged transversely of the drum of the drier.

Among the objects of the present inven tion are the provision of means whereby but a small portion of the air entering the drier is brought into contact with the dry heated material about to be discharged, the provision of means whereby a considerable part or the greater portion of the air admitted to the drier is brought into contact with the material being'treated therein at a point or points considerably beyond the neighborhood where the material is discharged, the provision of novel means for withdrawing the moisture laden air when its drying qualities have been substantially exhausted. the provision of means whereby the excess heat of the discharged material is utilized in heating the air entering the drier, and, generally, my invention relates to the improvement of apparatus of this character inl a number of important particulars.

With the foregoing and related objects in view, my invention consists in the parts, improvements and combinations herein set forth and claimed.

1n the accompanying drawings 1 have illustrated one form of apparatus in which my invention maybe embodied. 1t is to be understood, however, that said drawings are for the purpose of illustration only and that my invent-ion is not confined thereto but is of the scope defined by my claims.

In said drawingsl forming a part ofl this specification, 'and wherein the same reference numerals 5 are used to v'designate the rerrrr @Erica ven tional views on the lines 2-2, 3-3 and f 4-4, Fig. 1, and Fig. 5 is a fragmentary horizontal cross-sectional view taken on the line 5-5, Fig. 4. The drier shown in the drawings is of th rotating drum type', the drum or outer shellVV being indicated by the referencenumeral 10 and being provided with a number of ring shaped shoes 11 (two being shown in the drawings) upon which it is rotated, as upon rollers 12, 12 which may be supported in any convenient manner upon themachine foundation, as upon supports 13, 13. The

drum is arranged at* an angle about as shown and may be rotated in any convenient manner as, for example, by the pinion 14 meshing Awith the gear 15 secured to the drum, power being applied to the shaft of the pinion 14 as by means of gears 16 and 17.

The vmaterial to be'dried is supplied at the upper end of the drum as from a hopper 1S and may be fed through the supply opening 19 by any convenient means as, for example, by the worm 20 on the shaft 21 and which may be rotated from any convenient source of ,power as,`A for example, through gears 22, 23. The dried material is discharged from the opposite end of ther drum as through a peripheral aperture 24 from whence it passes into the chamber 25 and may be ydischarged therefrom as, for example, by a screw conveyer 26, the discharged material passing out throughV an aperture .27; As will be understood, the length, diameter and inclination of the vdryingdrum may be varied within wide limits,

said drum being shown comparatively short and thick in thel drawings for convenience of illustration.

The Huid used for drying, and which is, of course, preferably atmospheric air, passes through the drum in the reverse direction to the direction in which the material under1 treatment is passed. The heat of the dried material being discharged is preferably utilized by passing the incoming air along, above or in the neighborhood of the dried `material being discharged.' 1n the formv shown this're'sult is secured by admitting the air through the opening 27 along which it passes above the material being discharged Vand entering thechamber 25, as indicated by an arrow on Fig. Al. The means for controlling and distributing the air in its passagethrough the drum will be referred to hereafter. The air laden with the moisture extracted from the material under treatment is discharged from the drum at the opposite end thereof, in the form shown it being passed upwardly through a stack 2S. This construction, however, is not essential, as the air may be discharged from the upper end of the drum in any convenient manner or direction, and the draft through the drum may be created or accelerated by the use of any convenient suction apparatus such as a fan, vapor stack or the like (not shown) in accordance with established practice.

The heat used in drying may be supplied in any desired manner. In the form shown heat is supplied by means of a series of pipes 29 running lengthwise of the drum and set close to the walls thereof and preferably spaced a uniform distance apart. Heated gas or vapor, as steam, is supplied to the pipes 29 shown from a supply pipe 30 from which it is discharged in any convenient manner, as by branch pipes 3l arranged to turn on a supply chamber 32 and comQ municating with the heating pipes 29, which may be` connected up in sets to secure a uniform supply of the heating fluid as steam, as by means of cross pipes Such heating arrangements are well known and understood and l have, therefore, not at- Y tempted to show the same in detail.

Means are provided for lifting and showering the material under treatment across the drum when the latter is rotated. Vhen the heating pipes 29 as shown are provided, such pipes serve this function very efficiently, the material entering the spaces 34: between said pipes and between them and the walls of the drum and being gradually dropped down out of such spaces as the drum is rotated, such showering action extending well across the drum, as will be apparent from the shape or form of these intermediate spaces 34. If heat supplying means other than those shown are resorted to, they are preferably of such form as to perform such lifting and showering action, and if such be not the case, separate means for performing such function may be provided, as will be understood.

The means for controlling and distributing the drying air or other fluid preferably comprise a number of partitions extending transversely of the drum, one or more central air conduits and one or more of what I shall designate as combined collecting and distributing partitions, all of which are arranged in such manner as to obtain an eiicient drying action and to conserve a large portion of the heat ordinarily lost in such. apparatus. p

Then dry heated air is simultaneously brought into contact with air containing moisture and also with wet or damp materials from which the moisture is to be extracted, the capacity of such dry heated air for absorbing moisture is first used up in taking a share of the moisture from the moister air, as moisture from such source can be taken up by such dry heated air more readily than from the solid materials, and in such case the drying power of the hot, dry air is not utilized to the full extent possible in extracting moisture from the materials under treatment, but is wasted in taking moisture from the moister air with which it is brought into contact.

According to the present invention means are provided for bringing the dry heated air into Contact with the material being showered across the drying drum, and for keeping such entering air out of contact with the air which has already become moist by having absorbed moisture from the material under treatment. Furthermore, pro vision is made for drawing off the air which has been in contact with and has absorbed moisture from the material under treatment when it has become substantially fully charged with such moisture and is substantially incapable of effecting further drying action. Means are also provided for proportioning the amount of air to the needs of the material with which it comes into contact, thereby preventing the waste and in-` efficient action which results from supplying to the material under treatment a quantity of air in excess of its requirements. These results are secured by the division of the drying drum into Zones by means of transversely extending partitions, and by the provision of one or more internal conduits and of one or more collecting and distributing partitions designed to collect the air charged with moisture and to discharge it without further contact with the material under treatment and at the same time to supply fresh air to the material in the zone beyond the point where such collection is made.

The material under treatment in the form of apparatus shown being subjected to the greatest heat near the lower end of the drum where the pipes 29 are supplied with steam, and the greater portion of the moisture having been extracted by the time the material reaches this neighborhood, it is not necessary that any very considerable portion of the air supplied for drying shall come into contact with the material in this neighborhood, substantiallv as effec-tive a drying action being secured by passing a comparatively small quantity of air through such zone at a comparativelyslow' speed, as by passing a much larger amount or substantially all the air that enters `the drier through such neighborhood at a much higher speed..

distance from the material discharge endV thereof, and I substantially close the air entrance end of the drum as by means of an end wall 35, leaving only the narrow peripheral opening 24 which serves toward the bottom of the apparatus for the discharge of the material under treatment and to some extent in such neighborhood and substantially throughout the remainder of its extent for the entrance of drying air to the zone Z1. Such. airis heated somewhat by passing over the material being discharged on its entry through the passage 27, and by reason of the steam chamber 32 and pipes 31 being arranged within the chamber 25 through which such air is passed, and, of course, the air may be heated preliminarily before it is supplied to the opening 27. A considerableportion of the entering air being carried through central conduits, hereafter referred to, but a small part of such air is admitted to the Zone Z1 through the opening 24, and the rate of travel of such air is materially cut down in its passage through the Zone Z1 by making the partition P1 of somewhat smaller diameter than the end wall 35, thus leaving a substantially annular passa ge around the partition P1 and between it and the walls of the drum 10, through which the air is discharged from the Azone Z1, which annular passage is larger than the passage 24: through which air enters the Zone Z1. In this manner no excess air is passed through the zone Z1 and the air admitted passes through the zone Z1 comparatively slowly, and in passing therethrough takes up moisture from the material under treatment only, and none of the waste occurs which would result if excess air were admitted to such Zone or if the hot dry air were brought into contact with moister air 4 therein.

As the moisture of the material entering the Zone Z1 is comparatively low, and hut little is left to be taken out, the capacity of absorbing moisture from the air passing therethrough need not be entirely exhausted .when such zone has been traversed and this air may still be capable of absorbing additional moisture to a material further ex-.

tent, and it is, therefore, for this reason preferably permitted to pass into the next zone Z2 where the material under treatment is nearer the supply end and therefore contains additional moisture. A transverse partition P2. is provided Vbeyond the partition P1, the spaceA or Zone Z2 lying between such partitions P1 andP2. As thereis considerable moisture to be extracted vfrom thel material under treatment in such zoneit will be evident that fthe air entering from the Zone Z1 about the lpartition P1 will be insuicient to effecta proper drying action,

and therefore additional air is admitted cen,

trally of the zone Z2, as through the conduit l1 communicating with the chamber` 25 at the airfentrance end and arranged preferably centrally in the zone Z1, the air in such conduit C1. being heated in its passage through the Zone Z1. As Ywill be observed, the mouth of the conduitC1 through `which fresh, hot, dry airenters is kept as far as Vpossible from the opening about the partition P1 through which the air charged with more or less moisture from the zone Z1 en-V ters, so that the hot,'dry, fresh air entering through the mouthvof the conduit C1 into the zone Z2 first comes directly into contact with the material being showered through such zone and does not mingle with the air entering about the side walls from thezone Z1 until it hashad a chance to contactfwith and extract moisture from the material being showered across the Zone, and by the time the bodies of air coming from these two sources are mingled together the fresh airy has had an opportunity to become charged with the moisture taken directly from the material under treatment, so that its capacity for moisture extraction is not directed to any material extent to lessening the moisture content of the air admittedl about the partition P1 from the Zone Z1. This action and the movement of the air isindicated somewhat roughly by arrows on Fig. 1. It will be observed that the mouth of the conduit C1 is flared somewhat, but such flaring, while it serves to bring the air entering themouth of the conduit C1 into contact with a large amount of the material passing through the drum, does not act to bring such air into contact with the air entering about the partition P1 until the former body of air has had a-chance to be charged with moisture extracted directly from the material under treatment being showered across'the drum.

It is to be understood that thenumber and character of partitions and zones into which .y

the interior of the drying drum is divided may be varied according to the character of the substance to be dried, theproportion of moisturey carried thereby, etc. Whenever vthe moisture absorbing capacity of the air may be passed into other zones until substantially completely charged with moisture. For example, the air from the Zone Z2 may be passed out of that Zone through the space between the partition P2 and the wall of the drum and into another zone, as Z2, lying between the partition P2 and a combined moist air extractor and fresh air supply partition P2.

As the moisture absorption capacity of the air admitted to the Zone Z3 from the zone Z2 about the partition P2 is fairly well used up, it is desirable to introduce additional fresh air into this'zone, and such fresh air may be admitted centrally of the Zone through the conduit C2, which may be provided with openings 37, made as by cutting out and bending inwardly the sections 38, 38 of the wallsof the conduit C2, which is preferably made of sheet metal, thereby deiecting a considerable portion of the air passing through the conduit C2, which is preferably arranged centrally Within the conduit C1 and communicates with the air entrance chamber 25 and the air passing therethrough, being heated in the course of its passage through the Zones Z1 and Z2. A flaring shield as 39 is provided about the conduit C2 to direct the air passing through the openings 37 away from about the partition P2 and for screening the openings 37 to prevent the entrance of material dropping across the drum and passing therein. An additional guard as an angle rail 40 may be provided immediately beyond the openings 37 to prevent material from entering such openings. A similar angle guard or rail 40 may be placed about the conduit C2 immediately within the mouth of the conduit C1.

It will be seen that as in the zone Z2, the fresh air entering from the conduit C2 to the Zone Z2 is first brought into contact with the material falling across the drum before it contacts and mingles with the moister air entering from the Zone Z2 about the partition P2, so that as in Zone Z2, the absorbing action of the dry, fresh air is directed to the extraction of moisture from the material under treatment, and by the time the newly incoming air admitted centrally of the Zone Z3 is mixed with the moister air admitted thereto from. the Zone Z2, the moisture content of all the air therein is substantially alike.

By the time the air has traversed the Zone Z3 it ordinarily becomes so moisture laden as that its capacity for absorbing moisture is substantially exhausted, and at the neighborhood in the drier where this occurs, and whether the air before becoming so charged with moisture has passed through one, two, three or more Zones, provision is made for withdrawing or extracting the moisture laden air from the drier and taking it out as by the exhaust conduit or stack 28. This result may be accomplished in a variety of ways; in the form of apparatus shown such result'is obtained by taking the air in Zone Z3 from about its periphery and transferring it to the center of the drier and from thence delivering it directly to the exhaust conduit 2S. The partition P3 is a composite partition, and one of its functions is to serve as an extractor for such moisture laden atmosphere from the zone Z3. For this purpose the partition P3 is made up of two separate parts 4l and between which the moist air from the zone Z3 to be extracted may enter by means of the annular opening 43 directed toward the partition P2.

In the construction shown two opposite passages 44, 44 (Fig. are provided leading from the annular passage 43 to a short conduit C3 which is preferably hanged at its exit end, which end is preferably substantially opposite the opening to the conduit 28, such iange being preferably provided in order to insure the easy passage from the rotating conduit C2 to the discharge conduit 28 at all times. Such passages 44, 44 extend horizontally of the apparatus in the particular position illustrated. Another pair of passages 45, 45 (Fig. l) extend from the conduit C2 and communicate with outlets in the opposite side of the composite partition P3, as the substantially crescent shaped outlets 46, 46 which discharge fresh, dry air heated from the conduit C2 to the interior of the final Zone Z* into which the material to be treated is supplied directly as by the conveyer Q0. As it is essential that a space be left about the partitionP3 for the passage of the material under treatment, a 'cen tain amount of moisture laden air from the zone Z3 will pass through such opening directly into the. zone Z4, but, as in the other zones, and as indicated by arrows, it will be seen that the fresh, dry air is discharged in the neighborhood of the center of the drum through the crescent shaped openings 46 and has an opportunity to come directly into contact with and extract moisture from the material under treatment being showered across the drum. The air admitted about the partition P3 from the Zone Z3 and the fresh air admitted through th-e crescent shaped openings 4G after extracting the moisture from the material in the Zone Z4 mingling with the discharge air from the central conduit C2 passes out through the discharge conveyer 28, and in so doing assists to some extent in promoting the extraction of moist air through the passages 44 and the conduit C3, the action being on the familiar principle of the ejector.

As the material passesV through the drier in a downward direction, the edges of the various partitions are preferably disked somewhat, as indicated at 46, 46 to present a rounded surface where the material passing through the drier comes in contact therewith as it passes from zo-ne to zone.

In orderl to control the relative amounts of air which pass out from the conduit C2 through the openings 38into the zone Z3 and through the passages @l5 and into the zone Z* in the proper proportions for securing the best results in such zones, I preferably provide a damper 47 which may be pivoted at 48 and is controlled from the exterior of the apparatus. For this purpose I have shown a rod 419 attach-ed to the damper pivotally at 50 and extending beyond the end wall of the apparatus and terminating in a handle 51. Such end wall preferably is provided with doors 52, 52 which are norinally closed but may be opened, and any means for adjusting the rod 49 carrying the handle 51 in any desired position may be provided.V In the form shown a plurality of holes 53, 53 are formed in the rod 49 in the neighborhood where it projects -through the casing, and the same may be secured inv adjusted position as by pins passed through such holes in any convenient manner. As will be seen, if the damper 47 is turned toward the closed position more air will be discharged throughv the openings 3'7-v into the zone Z3 and less into the passages 45 and into the zone Z4, and when the damper 4L? is turned toward the open position an opposite effect will be secured. v

Vhile provision is made, 'as already described, for preventing the material being treatedv from getting into the central air conduits, it may happen that, notwithstanding such precautions, parts of the material under treatment and the dust and chaff therefrom may at times get into such flues or conduits, and if a sufficient amount should collect therein the operation of the apparatus would be interfered With. i I have accord# ingly provided a simple means for ejecting from such flues any material which may become lodged therein. Such means in the form of apparatus shown kconsists of a pipe 54 placed into communication with the interior of thev steam chamber 32 and con trolled by a hand valvev 55, access to which may be obtained by opening one or more of the doors 52. Said pipe 54 is provided with a series of discharge Vnozzles arranged so that they are directed toward spaces immediatelywithin the air discharge passages. In the form shown I have illustrated two such sets of nozzles 56 and 57 within the conduit C2 and a third set of nozzles 58 within the conduit C3. As will be evident, the location and number of suoli discharge nozzles, which are preferably directed toward the air discharge end of the conduits, may be varied in order to secure the most effective cleaning action when it is desired to blow out any material whichis lodged in.

the air flues. As will` be seen, thesteam from such nozzles entersthe annular portion of the drum in which the material is showered only beyond the partition P2 and does not enter either ofthe zones Zl or Z2, so that it is feasible, should occasion arise, to open the valve for blowing lodged material yout of the conduits C2 and C2 during the operation of vthe apparat-ns and without materially lessening the dryness of thematerial passing out of thedrier at the dis'- charge end. Y Y v Any convenient means for supporting the `conduits,,partitions and the like parts may be resorted to. As shown, barsorlstraps 60 secured at their outer ends to the drum 10 are provided for the purpose, i'

While I have illustrated in the present drawings two of the simple partitions P1 and P2 and a single combination extractor and dry air supply partition structure P3, it is to'be understood that the number land location of the various partitions and other distributing and controllingdevices for the air passing through' the apparatus may be varied within wide limits so long as the ad* vantageous results or any thereof secured by' thefeatures ofy the construction herein disclosed are obtained. i Y

`It will be seen that-apparatus in accord ance with my 'invention has numerous points of advantage, among which are the following: The heatof the discharged material is utilized by imparting it to the incoming air; the material under treatment is at all times brought into contact with fresh, dryV air supplied in a quantity and moved at a speed calculated to secure the mosteffective eX- traction of the moisture;` where moist air anddry air are admitted to the same parts of the apparatus the dry air is brought into contact with'the material to be Idried so as to extract moisture therefrom before it is permitted to contact and mingle withv the moister airg'the kmoisture laden `air 'when charged with moisture to an extent to render.

it of no further'value as a vehicle for further moisture'extraction is taken out of the drier and discharged therefrom without permitting it to actdetrim'entally by coming into further contact with the dry air or` the material being dried; provision is made by means of the damper for adjust-ing and regulating the disposition'of` the 'incoming air to different parts nofthe apparatus in order to `secure the` most effective results the air flues are guarded from ingress of material under treatment, and'if it ,should happen that any such chaff or other material gets into: the flues it is readilypossible to drive it out and preventany possibility of clogging, and this without materially interfering with the ellicient operation of the apparatus. Still other features of advantage need not vbe recited infurther detail.V L

isc

Cil

It is to be understood that the construction shown is for the purposes of illustration only and for affording a clear understanding of the principles of my invention, and that my invention is not limited thereto, but that numerous departures from and changes in the particular construction illustrated may be resorted to within the scope of my claims and without departing from the spirit of my invention or sacrificing any of the advantages thereof.

Having thus described my invention, I claim:

l. Ina drier, an inclined rotating drum. means for feeding material thereto at one end, means for discharging it dried at the other end, means for causing air to traverse said drum in a direction opposite to the direction of movement of the material being treated, and a series of transverse partitions within said drum and spaced away from the walls thereof for distributing the air in its passage through the drum, substantially as. set forth.

2. In a drier, an inclined rotating drum, means for feeding material thereto at one end, means for discharging the dried material from the other'end comprising a discharge conduit, and means for supplying air to the drum in a direction Vopposite to the direct-ion of movement of the material under treatment, said Vair being passed through the conduit whereby the heated dried material is discharged to thereby become heated before it enters the drum, substantially as set forth.

3. In a drier, an inclined rotating drum through which material is passed lengthwise in one direction, means for causing air to pass through the drum in the opposite direction, and a series of transverse partitions in said drum and spaced away from the walls thereof for controlling and distributing the drying` air in its` passage through the drum, substantially as set forth.

4l. In a drier, an inclined rotating drinn, means on its side walls to lift and shower down material under treatment, means for causing a current of air to travel lengthwise through said drum, a series of transverse partitions in said drum, and air supply means arranged centrally of said drum, said partitions Vand air supply means serving to control and distribute the air in its passage through the drum, substantially as set forth.

In a drier, an inclined rotating drum, means on its side walls to lift and shower down material under treatment, means for causing a current of air to travel lengthwise through said drum, a series of transverse partitions in said drum and spaced away from the side walls thereof, and centrally arranged air supply means in said drum cooperating with said partitions to control and distribute the air in its passage through the drum, substantially as set forth.

6. In a drier, an inclined rotating drum,

lifting and showering means in said drum, a

series of transverse partitions in said drum, and means for supplying fresh air to the spaces between said partitions, substantially as set forth.

7. In a drier, an inclined rotating drum, means for supplying material thereto at its upper end, means for discharging material dry at the other end, means for causing air to traverse said drum in a direction opposite to the direction of travel of the material under treatment, and means whereby partof the air is caused to enter said drum near its walls at the lower end and a further part is delivered into said drum at a distance from the lower end, substantially as set forth.`

S. In a drier, an inclined rotating drum through which material is fed in a downward direction, means for creating a current of air upwardly through said drum, a series of transverse partitions in said drum, and an air conduit arranged centrally in said drum and adapted to prevent the contact of the air passing therethrough with the material under treatment in such drum until the air has passed therein to a distance beyond the end at which the air enters, substantially as set forth.

9. In a drier, an inclined rotating drum, an air conduit arranged centrally in said drum, and a series of partitions extending outwardly from said air conduit to the neighborhood of the walls of the drum, substantially asset forth.

10. In a drier, an inclined rotating drum, means for admitting air into said drum and bringing it into contact with the material therein under treatment, and means for removing such air from the drum when moisture laden and preventing it from coming into contact with the material under treatment in said drum beyond the point from which it is removed, the air under treatment traveling through'the drum in opposite directions, substantially as set forth.

11. In a drier, an inclined rotating drum, means for feeding material into said drum at its upper end, a partition in said drum adjacent to the upper end, means for supplying fresh air to the space beyond said i partition, and means for discharging the moisture laden air from the opposite side of the partition without its coming into contact with the space on the first named side of said partition, substantially as set forth.

1Q. In a drier, an inclined rotating drum, means for supplying material thereto for treatment at the u per end thereof, means for removing dried material at the opposite end, means for directing air into contact with the material -infsaid drum until it becomes laden with moisture, means for withdrawing the moisture laden air at such neighborhood, and means y for supplying fresh air into contact withtlie material under treatment beyond such neighborhood, substantially. as set forth.

13. ln adrier, an inclined rotating drum, means for supplying material thereto for treatment at the upper end thereof, means air into contact with the material in said drum, and means for withdrawing the moisture laden air from a point in said drum below said point of material supply, the air and material under treatment traveling in opposite directions, substantially as set forth.

15. In a drier, an inclined rotating drum, means for bringing air into contact with the material in said drum for a portion of its length and then withdrawing such moisture laden air, and means for bringing fresh air into contact with the material to be treated in the drum beyond the point of such withdrawal, substantially as set forth.

16. ln a drier, an inclined rotating drum, means for feeding material thereto at its upper end, means for discharging the dried material at its opposite end, and means for conducting air into said drum in theneighborhood of the periphery thereof and also` in the neighborhood of the center thereof, substantially as set forth.

17. In a drier, an inclined rotating drum, means for feeding material to said drum at its upper end, means for removing the dried material at its opposite end, means for causing a current of air to pass through said drum in the opposite direction, a series of transversely arranged partitions in said drum and spaced away from the wallsthereof. and substantially dividing the space of the drum into a plurality of chambers, means for admitting air into the lowermost of said chambers around the outer walls thereof, a central conduit passing through said first chamber and adapted to supply air to the second chamber into contact with the material therein, and means arranged within said conduit and passing' beyond the end thereof and through the second chamber and adapted for discharging fresh air into the ,third chamber, substantially as set forth.

18. In adrier, anA inclined rotating drum, means for feeding material thereto at one end, means for discharging the dried ma terial at the other end, means for causing a current of air to traverse said drum in contact with the material therein until laden `with moisture, means for withdrawing said air when moisture laden without further contact with the material in the drum, and means for supplying' fresh air into .contact with the material under treatment in the ,drum beyond the point where the moisture laden air is withdrawn, substantially asset forth.

19. ln a drier, aninclinedrrotating drum, means for supplying material thereto at one end, means for discharging the dried materia-l at the opposite end, a conduit at the upper end thereof whereby air is discharged, a partition in said drum, means for conducting moisture laden air from they lower sidel of said partition direct to said conduit, and means for supplying fresh air beyond said partition and into Contact with the material in the drum between the partition and the material supply end, substantially as set forth.

20. ln a drier, an inclined rotating drum,

partition therein, an air discharge conduit, means for conducting moist air from the space in said drum on one side of said partition to said conduit, and means for supplying fresh air to the spa-ce in the drum on the opposite side of said partition and for conducting it from thence into said conduit, substantially as set forth.

21. In a drier, an inclined rotating drum, a partition therein, a central conduit on each side of said partition, and means for causing the passage of air from a space be' tween the conduit and drum on one side of said partition and into the conduit on the other side and vice versa, substantially as set forth.

22. In a drier, an inclined rotating drum, a pair of transversely extending partitions set close together, a conduit on each side of said partitions and said partitions being provided with passages whereby air from the conduit on one side is discharged outside the conduit on the other side and air from the outside of the conduit on the first side of the partition is admitted into the conduit on the opposite side of the partition, substantially as set forth.

23. In a drier, an inclined rotating drum, means for feeding material to be dried thereto at its upper end, means for discharging said material at the lower end, a central air conducting conduit extending Vfrom the lower end of the partition to the neighborhood of its upper end, means on the end of Said conduit for discharging the air supplied thereby into contact with the material to be treated in the drum, and

ymeans centrally arranged in the drum for discharging the air in said drum from hetween said drum and the walls of said con duit, substantially as set forth.

24. In a drier, a dru1n,'an internal air conduit communicating with the interior of the drum in two separate regions, and a damper in said conduit between the two neighborhoods where it communicates with the interior or said drum, substantially as set forth.

25. In a drier, a drum, an internal air conduit, a partition extending across said drum and through which said conduit passes, said conduit being provided with eXit openings into the drum on each side of the partition, and a damper for controlling the amount of air admitted to said openings, substantially as set forth.

26. An air controlling and distributing apparatus for insertion in a drier drum and comprising a series of partitions adapted to extend transversely of the drum of the drier, and one or more central air conduits passing through said partitions, substantially as set forth.

n testimony that I claim the foregoing, I have hereunto set my hand, this 16th day of March, 1915.

CHARLES FREDERICK S"EHL1N.

lVitnesses ELA. JonNsoN, 1WM. H. CAMFIELD.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents.

Y Wa shin gton. D. C."

It is hereby certied that in Letters Patent N o. 1,167,853, granted January 11, 1916, upon the application of Charles Frederick Stehlin, of New Rochelle, New York, for an improvement in "Driers, an error appears in the printed speeication requiring correction as follows: Page 6, line 113, claim 10, after the Word air insert the Words and material; and that the said Letters Patent should be read With this correction therein that the same may conform to the record of the case in the Patent Ol'iice.

Signed and sealed this 8th day of February, A. D., 1916.

R. F. WHITEHEAD,

Acting Commissioner of Patents.

[SEAL] 

